The present invention relates generally to a custom eyeglass manufacturing method. More specifically, the present invention pertains to developing a manufacturing method that combines a wavefront measuring device with an imaging system that acquires data from a patient""s head. The present invention is particularly, though not exclusively, useful for spectacles that correct for aberrations other than sphere, cylindrical, and axis.
Current eyeglass manufacturing technology does not provide lenses that precisely correct a patient""s wavefront aberrations. However, new manufacturing techniques that make use of epoxies, cured to different indexes of refraction matching the wavefront aberrations of a patient, present new manufacturing challenges. Specifically, alignment of the spectacle with the patient""s optical axis is of the utmost importance when making spectacle lenses that correct for aberrations other than spherical, cylindrical, and axis. In order to ensure such precise alignment, the distance of the lenses from the cornea""s apex, the pupil distance, and the centering of the optic axes of the spectacle lens with respect to the patient""s pupil (or visual axis) need to be accurately measured.
Accordingly, it is an object of the present invention to provide a manufacturing method which determines the exact location of the nose and ear moldings of a pair of spectacles with respect to the patient""s pupils, corneal apexes, and any other parameters necessary to quantify a patient""s head and face for future eyeglass fitting.
The custom eyeglass manufacturing method of the present invention includes a system that combines a wavefront measuring device with an imaging system that acquires data from a patient""s head. The patient looks into the wavefront measurement system that includes three or four additional cameras for viewing of the patient""s head and eyes during examination. In the simplest case, the wavefront measurement device could be a refractor, autorefractor, or phoroptor. In a preferred embodiment, one camera each is mounted to the left and right side of the patient""s head in order to obtain an image of the respective side views of the patient""s head, including the patient""s ears, nose, eyes, and apexes of the corneas. A third camera is placed in front of the patient""s face in order to obtain a frontal view, including the nose, eyes, and in particular the pupils of the patient. The frontal view could be covered by one camera, or by two cameras with each covering the area around each of the patient""s eyes.
During the wavefront measurement, various gazing angles of the patient""s eyes are taken. The optical aberrations for various tasks are measured such as, the patient looking straight ahead for far distance viewing, the patient looking at a lower angle for computer reading applications, and an even lower gazing angle for close-up viewing or reading. The viewing cameras simultaneously acquire images of their respective viewing area. The images are then processed by a computer. The output of the computer is the precise measurement of the patient""s pupils, center of the pupils, pupil distance, width of face, ear location, distance of corneal apex from the wavefront measuring device, distance from ear to corneal apex, and other parameters necessary to custom fit a pair of eyeglasses.
In order to help the computer program find some of the areas automatically, pre-formed or custom-made moldings with or without integrated registration markers could be used with this system. In the simplest form, the patient would wear an existing eyeglass frame of known dimensions, which might have registration marks attached to it. The registration marks could be affixed anywhere on the frame, however, locations behind and in front of the ears, and near the nose might be effective.
A moldable material is then used around the patient""s ears and nose in order to form a mold to be later used to construct custom nose and ear pads. If registration markers are not applied directly to the frame, then they may be added to the molds before they cure. After imaging the patient, the computer would have stored a right and a left side view, and one or two frontal views of the patient wearing the test frame with the moldable pads.
From these images, the exact location of the nose and ear moldings with respect to each other and with respect to the patient""s pupils, corneal apexes, and the test frame can be determined. Using current reproduction processes, the ear and nose moldings obtained from the patient would be duplicated or transformed into custom eye-glass frames or custom eye-glass hinges and nose pads. From the position information obtained through imaging the test frame, any other eye glass frame could be fit or custom manufactured to fit the patient.